Add unit tests for ERC1155 Discount Validator (#40)

* Init

* Add unit tests for ERC1155 Discount Validator

test/L1Resolver/L1ResolverBase.t.sol

@@ -1,5 +1,5 @@
 //SPDX-License-Identifier: MIT
-pragma solidity 0.8.23;
+pragma solidity ^0.8.23;
 
 import {Test, console} from "forge-std/Test.sol";
 import {L1Resolver} from "src/L1/L1Resolver.sol";

test/discounts/ERC1155DiscountValidator/ERC1155DiscountValidatorBase.t.sol

@@ -0,0 +1,19 @@
+//SPDX-License-Identifier: MIT
+pragma solidity ^0.8.23;
+
+import {Test} from "forge-std/Test.sol";
+import {ERC1155DiscountValidator} from "src/L2/discounts/ERC1155DiscountValidator.sol";
+import {MockERC1155} from "test/mocks/MockERC1155.sol";
+
+contract ERC1155DiscountValidatorBase is Test {
+    ERC1155DiscountValidator validator;
+    MockERC1155 token;
+    uint256 tokenId = 1;
+    address userA = makeAddr("userA");
+    address userB = makeAddr("userB");
+
+    function setUp() public {
+        token = new MockERC1155();
+        validator = new ERC1155DiscountValidator(address(token), tokenId);
+    }
+}

test/discounts/ERC1155DiscountValidator/IsValidDiscountRegistration.t.sol

@@ -0,0 +1,20 @@
+//SPDX-License-Identifier: MIT
+pragma solidity ^0.8.23;
+
+import {ERC1155DiscountValidatorBase} from "./ERC1155DiscountValidatorBase.t.sol";
+
+contract IsValidDiscountRegistration is ERC1155DiscountValidatorBase {
+    function test_returnsFalse_whenTheClaimerDoesNotHaveTheToken() public view {
+        assertFalse(validator.isValidDiscountRegistration(userA, ""));
+    }
+
+    function test_returnsFalse_whenAnotherUserHasTheToken() public {
+        token.mint(userA, tokenId, 1);
+        assertFalse(validator.isValidDiscountRegistration(userB, ""));
+    }
+
+    function test_returnsTrue_whenTheUserHasTheToken() public {
+        token.mint(userA, tokenId, 1);
+        assertTrue(validator.isValidDiscountRegistration(userA, ""));
+    }
+}

test/mocks/MockERC1155.sol

@@ -0,0 +1,12 @@
+//SPDX-License-Identifier: MIT
+pragma solidity ^0.8.23;
+
+import {ERC1155} from "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
+
+contract MockERC1155 is ERC1155 {
+    constructor() ERC1155("") {}
+
+    function mint(address to, uint256 id, uint256 value) public {
+        _mint(to, id, value, "");
+    }
+}